Crosslinking, polymer-ceramic transformation

The connection between polymer chemistry and ceramic science is found in the ways in which linear macromolecules can be converted into giant ultrastructure systems, in which the whole solid material comprises one giant molecule. This transformation can be accomplished in two ways—first by the formation of covalent, ionic, or coordinate crosslinks between polymer chains, and second, by the introduction of crystalline order. In the second approach, strong van der Waals forces within the crystalline domains confer rigidity and strength not unlike that found when covalent crosslinks are present. 

Using similar procedures polycarbosilanes could be obtained which were transformed into nearly stoichiometric silicon carbide [98]. In order to obtain higher ceramic yields the precursors were thermolyzed at 300 °C for 3 h imder argon prior to pyrolysis. Crosslinking of the polymer chains occurred during the thermolysis under elimination of hydrogen and methylsilanes (Scheme 8). 

Matsumoto K, Matsuoka H (2005) Synthesis of core-crosslinked carbosilane block copolymer micelles and their thermal transformation to silicon-based ceramics nanoparticles. J Polym Sci A Polym Chem 43(17) 3778-3787... 

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